COATED AND LAMINATED FABRICS FOR FUEL CELLS.

The electrical characterization of the air/hydrogen polymer electrolyte membrane fuel cell is done. The effect of hydrogen flow rate on voltage, resistance and current is investigated at standard conditions. There is an optimum flow rate that gives the maximum voltage and current. The effect of load on thickness and resistivity of various gas diffusion layers (GDL) is measured. Loading reduces the thickness and resistivity of the GDLs. New GDL structures are being made with wet-lay process. A low cost composite polymer electrolyte membrane was developed. It can increase the fuel cell durability when operated at below 80°C. The polymer electrolyte membrane was prepared from Nafion®/polypropylene composite (70:30 weight ratio). The addition of polypropylene to the composite membrane showed a decrease in the flow rate of back diffused water from cathode to anode giving rise to a steadier water content (water molecules per sulfonic acid group) at the anode required for the efficient distribution of proton concentration. The polypropylene used in the membrane decreases the cost of the membrane. However the low performance of the composite membrane should be addressed. A computational model was established using COMSOL package to simulate the current density distribution and the water management in the Nafion® 117 membrane and Liquion® LQ-1115/polypropylene composite membrane operating at 20°C. The modeling results were validated with experimental data attained using a single fuel cell kit for the polymer electrolyte membranes. [ABSTRACT FROM AUTHOR]